Boron halides as reagents in inorganic syntheses. Part II. A further general method for the preparation of anhydrous bromides and iodides: halogen exchange reactions
Abstract
Metathetical exchange reactions of (i) boron tribromide with anhydrous chlorides of AlIII, TlI, SnIV, AsIII, SbIII, SbV, BiIII, TiIII, TiIV, ZrIV, HfIV, VIII, NbV, TaV, MoV, WVI, FeIII, CoII, NiII, PtIV, CuII, and CdII; (ii) BBr3 and oxychlorides of SVI and VV; and (iii) Bl3 with anhydrous chlorides of SnIV, SbIII, and TiIV, provide a general method of synthesising anhydrous bromides and iodides. Boron tribromide reacts with the cluster chloride Pt6Cl12 forming the new mixed halide (PtBrCl)n. The exchange reactions are essentially quantitative, and separation of pure products is readily achieved.
The general reaction between boron tribromide and metal, metalloid, and non-metal oxides for preparing anhydrous bromides and oxybromides has been extended. Thus the reactions of BBr3 with oxides of GaIII, InIII, TlIII, SnIV, BiIII, TeIV, ZrIV, NbV, TaV, MoIV, MoVI, FeIII, LaIII, UIV, ZnII, HgI, and HgII, and of Bl3 with oxides of SnIV and TaV, are reported.
Vibrational spectra for the halides NbOBr3, NbBr5, TaBr5, and Pt6Br6Cl6 are described.